Glass fiber packages are commonly manufactured by discharging a plurality of molten glass streams from a heated bushing, attenuating the plurality of glass streams into a plurality of fibers, passing the fibers through an applicator to apply an aqueous based size to the fibers. After this the fibers are gathered into a strand at a gathering shoe and are then wound on a collet to produce a glass fiber package. This package is then dried to evaporate the water from the aqueous based size.
Both manufacturers of such glass fiber packages and users of such packages are well aware that a problem exists which is generally referred to in the art as "migration". Migration is visually observable as a discoloration of the fibers in the package. It results during the drying process when the water is migrating outwardly in the package, taking a portion of the size with it, and thereby deposits more size than normal towards the outer periphery of the package and at various random locations along the way. One way the migration problem has been dealt with is to simply strip away the outer layers from the package to remove the discolored fiber. This, of course, wastes a good deal of material and is uneconomical. Furthermore, the edges of the packages, as when forming a Type 30.RTM. square-edged package, can also have this migration problem and they, of course, cannot always be stripped away. Otherwise there would be no remaining package. This means that in use there are periodic "chinks" of discolored material resulting from this edge migration occurrence. Users of such packages, of course, find this visual occurrence of "chinks" to be unsatisfactory. Thus, it will be seen that there is a problem in the art which needs to be solved.
The present invention solves this problem in a cost effective manner by eliminating migration. By practicing the present invention there will no longer be a need for stripping to remove discolored glass fiber strands because the cause of the discoloration has been eliminated. Additionally, the present invention eliminates current drying ovens thereby providing for more economical processing because of the elimination of labor and eliminating the utilization of additional energy. It has even been observed that increases in fiber tensile strengths have been obtained by using the present process in contrast to the prior art commercial processing technique. Moreover the present invention can be practiced without any "fuzz" problems. Finally the application efficiency of the size and the formation of a more uniform dried size coating on the fibers is also realized in accordance with the present invention.